1. Field of the Invention
The present invention relates to a film winding device in which rotation of a winding motor housed in a film winding spool is transmitted to a winding spool through a reduction mechanism. In particular, the present invention relates to the reduction mechanism of such a film winding device.
2. Description of the Related Art
Due to the current trend toward a miniaturization of cameras, in film winding mechanisms of such cameras, the drive motor is usually housed in the film winding spool. Conventionally, in this kind of device, an output shaft of the drive motor projects from the winding spool and is provided with a drive gear, and rotation of the drive gear is transmitted to the winding spool through a reduction mechanism in order to wind the film on to the winding spool. Conversely, when the film is to be rewound, rotation of the drive motor is reversed and is transmitted to a rewinding shaft through rotation switching mechanism, whereby a rotation of a shaft of a film cartridge is reversed, and the film wound onto the winding spool is rewound into the film cartridge.
In this conventional device, the reduction mechanism is used to reduce the rotational speed of the driver motor, and to transmit the reduced rotational speed of the drive motor to the winding spool. Conventional reduction mechanisms comprise a gear train including a plurality of gears having a different number of teeth. Therefore, the size of the reduction mechanism is relatively large; and this is a disadvantage when attempting to reduce the size of a camera. Further, since conventional reduction mechanisms have many parts, the manufacturing and assembly costs are high.